This invention relates generally to a system for dispensing fluids, and more particularly to a sealant delivery system and apparatus for application of a sealant compound material to can lids of the type disclosed in U.S. Pat. No. 4,262,629, the disclosure of which is incorporated herein by reference.
In general, the apparatus of U.S. Pat. No. 4,262,629 comprises a rotary can lid feed mechanism having a series of pockets which are advanced through a downstacker area to laterally shift each lowermost lid in succession of the stack of lids along an arcuate guide path into each of a series of shallow recesses formed in a rotary chuck table. The rotary chuck table has a series of lift chucks disposed in normally lowered position beneath the recesses, and a rotary drive is operative to synchronously rotate the table and lift chucks at a predetermined rate of speed. A cam member located in the path of travel of the lift chucks is operative to advance each lift chuck in succession when it is received at a first station between a normally lowered position and a raised position through a distance corresponding to two stations, after which the lid is lowered as it is advanced to a third station and discharged into a collection area. The empty recess then continues through a distance corresponding to three more stations before it picks up another can lid. An upper sealant gun assembly includes a spring-loaded chuck aligned with each recess to as to be engageable with each lid as it is raised by the lift chuck to activates an associated sealant gun in response to such engagement. The sealant is discharged from the gun as the can lid is caused to rotate about its own axis by rotation of the lift chuck through the first two stations so as to uniformly deposit the lining material into the groove of each can lid in succession. Again, following application of the sealant, the can lid is lowered by the lift chuck, then disengaged so as to permit the can lid to be discharged from the table preferably by the rotary speed of rotation of the table into a discharge or collection area. Feed interrupt mechanism is provided for interrupting advancement of the can lids from the downstacker area in passing in the event of misalignment of a lid; also, an interrupt mechanism is provided in association with the sealant gun to interrupt delivery of sealant in the event that the can lid is not properly aligned with respect to a recess on the chuck table. Preferably, both interrupt mechanisms are controlled by a common sensor in the rotary feed mechanism; however, a separate sensor is provided on the upper chuck assembly to interrupt supply of sealant. Apparatus of this type has been successfully employed with sealant material made from a non-abrasive, non-corrosive solvent base compound which does not present any significant problems in the sealant delivery system. However, the sealant delivery system of this type of apparatus has been found to be unsatisfactory for an abrasive corrosive water-based sealant compound.